Various clients in a communication system exhibit different capabilities, and therefore it is necessary for an origin server to adapt the capability of a user client to a user demand based upon a certain processing way. For this purpose, it is necessary to enable capability information of a client to be exchanged between the origin server and the user client, and a User Agent Profile system provides a representation method for exchanging capability information of a client between the user client and the origin server, in which the capability information of the client is represented with UAP information, so that applications of a WAP service can be supported well.
Particularly, the capability information of a client includes, but is not limited to, the following information:
Hardware information, which refers to hardware features of the client, including information on a type, a model, a display screen size, supported input methods and output styles, and the like, of the client device;
Software information, which refers to a software operation environment of the client, including information on an operation system of the client device, whether video and audio encoding and decoding operations are supported, language options for a user, etc.;
A browser program, which refers to information on a set of features descriptive of an HTML browse application program;
Network features, which describe information on a network related structure and environment, such as a network bearer, etc.;
WAP features, which describe information related to the WAP supported by the client device, such as a WML browse capability and feature, etc.; and
PUSH features, which describe information related to the PUSH supported by the client device, such as the maximum length of a short message that the client device can support, the maximum size of a short message that the client device can store.
In the UAP system, the capability information related to the user client can be provided to the origin server, so that the origin server can tailor the service contents to be issued to the user client in accordance with the capability information of the user client, thereby providing the service contents to the user client by using a format which is the most accordant to the capability of the user client.
With reference to FIG. 1, which shows a structural block diagram of main components of an existing UAP system, primarily including:
A UAP client: it typically refers to a UAP enabled intelligent client device, such as a mobile phone or a PDA. To initiate a network session connection to the network side, the UAP client puts its UAP related information (for example, a URL of a location where its capability information is stored) into a HTTP request message or a WSP request message and sends it to a WAP gateway or an origin server.
The origin server: it is a UAP enabled service application server, such as a PUSH server; the origin server can process the HTTP request message containing the UAP related information, which is sent from the UAP client, obtain UAP information corresponding to the UAP client from a UAPfile repository in accordance with the UAP related information (for example, the URL of the location where the capability information is stored) carried in the request message, and tailor service contents requested by the UAP client in accordance with the obtained UAP information and then issues the service contents to the UAP client.
The WAP gateway/a proxy cache: the WAP gateway, which is located between the UAP client and the origin server, is adapted for conversion between the WAP protocol and the HTTP protocol at the UAP client side, supports an operator on extending its own set of capabilities, and supports combining and then forwarding static information (i.e. the URL of the location where the capability information is stored) reported from the UAP client and dynamic information (such as capability information modified by the UAP client at the same time) to the origin server.
The UAPfile repository: it is adapted for storing UAP information of respective UAP clients, and allows the origin server or the WAP gateway to obtain UAP information corresponding to a UAP client in accordance with UAP URL information reported from the UAP client, where the UAP repository can be established or maintained by a client manufacturer or a network operator.
With reference to FIG. 2, a schematic diagram of a process in which the existing UAP client initiates a request to the origin server is shown, in which:
1. The UAP client initiates a webpage browse request to the origin server, and at this time, a session connection will be established between the UAP client and the origin server, the UAP client carries its UAP related information (which typically is the URL of the location where its UAP related information is stored) in the session connection request message, and the origin server obtains the corresponding UAP information from the UAPfile repository in accordance with the URL information carried in the session connection request message sent by the UAP client.
2. The origin server returns to the UAP client a response message, and if the origin server can process the UAP information properly, then the returned response message is OK; otherwise, an error code is returned.
With reference to FIG. 3, a schematic diagram of a process in which the existing UAP client reports on its own initiative the information on a capability change to the origin server when its capability information is changed is shown, where a session initiation phase exists only when the UAP client is connected to the origin server. During the session initiation phase, a session is maintained between the UAP client and the origin server and will not be disconnected until the connection between the UAP client and the origin server is closed; during the procedure, the origin server buffers UAP information of the UAP client; and during this procedure, the UAP client, once discovering that its UAP information is changed, notifies the WAP gateway or the origin server about the change of its UAP information in a Resume way, and this notification may occur for many times while the UAP client browses related contents:
1. The UAP client carries its changed UAP information in a XML form in a message header x-wap-profile-diff, and this message header is typically generated by the UAP client and is appended to a request message sent to the origin server to transport the information on the UAP change;
2. Upon receipt of the message header x-wap-profile-diff, the origin server feeds back a corresponding response message (including whether the origin server supports the use of UAP information, a reason for an error, etc.) based upon a message header w-wap-profile-warning.
Upon receipt of the changed UAP information of the UAP client, the origin server tailors the related service contents requested by the UAP client in accordance with the updated UAP information.
In the existing UAP system, however, the user client will trigger on its own initiative reporting of its UAP related information and/or its changed UAP information and the like to the origin server only if the user client initiates a browse request to the origin server or discovers, while browsing the service contents, that its UAP information is changed, but the origin server is supported on neither a capability of interrogating on its own initiative about the UAP information, nor a capability of information exchange with the user client, resulting in that the origin server cannot control reporting of the UAP information by the user client based upon a certain policy, accordingly, a specific implementation of the UAP system may be inflexible.